超声激励封孔对等离子喷涂Al_2O_3-13%TiO_2涂层耐腐蚀性能的影响

Influence of Sealing Treatments with Ultrasonic Excitation on Corrosion Resistance of Plasma-sprayed Al_2O_3-13%TiO_2 Coatings

对于等离子喷涂Al_2O_3-13%TiO_2陶瓷涂层,以有机硅透明树脂为封闭剂,分别采用常规浸渍封孔和超声波激励封孔方法在不同温度下进行封孔处理;采用10%HCl溶液浸泡试验和电化学腐蚀试验比较了封孔前后涂层的耐腐蚀性;应用光学显微镜、扫描电镜和能谱仪对腐蚀形貌及产物进行检测和分析。结果显示,封孔处理有效地降低了涂层孔隙率,60℃超声激励封孔L后孔L隙率比未封孔涂层降低了70.53%;超声激励封孔效果优于常规浸渍封孔,全浸泡腐蚀结果显示,60℃封孔时施加超声激励,能提高封孔效率,延长涂层寿命。电化学试验结果表明,60℃、40℃超声激励封孔,封孔L后涂层腐蚀速率降低,耐腐蚀性能得到有效提高。

The corrosion resistance of plasma-sprayed Al2O3-13 · TiO2 （AT13） coating was studied before and after sealing with silicone resin, as sealing agent and using the technigues of conventional impregnating and ultrasonic excitation respectively, at different temperatures. The performance after different sealing treatments were studied by 10% HCl immersion testing and electrochemical testing. Morphology and products were analyzed by scanning electron microscopy （SEM） , optical microscopy （OM） and energy disperse spectroscopy（EDS）. The results showed that sealing treatments of silicone resin reduced the porosity of plasma-sprayed AT13 coatings effectively. The porosity of coatings sealed at 60 ℃ with ultrasonic excitation decreased by 70. 53% compared to the unsealed coatings. Sealing treatment with ultrasonic excitation was more effective than conventional impregnating sealing. Sealing treatment at 60 ℃ with ultrasonic excitation could prolong the service life and increase the corrosion potential by 30% compared to conventional impregnating sealing of coatings. And sealing treatment at 40 ℃ with ultrasonic excitation made the corrosion current decreased by 75% compared to conventional impregnating sealing of coatings. The sealing treatments with ultrasonic excitation reduced the corrosion rate and enhanced the corrosion resistance of ceramic coatings effectively.